DfR Solutions' Insights

Reballed Ball Grid Array Reliability Under Shock and Vibration

The electronics assembly market has experienced a material shift from lead (Pb) based solders to Pb-free solders. This is a result of the widespread adoption of Reduction of Hazardous Substances (RoHS) legislation and practices in commercial industry. As a result, it is becoming increasingly difficult to procure commercial off-the-shelf (COTS) components with tin-lead (SnPb) solder balls or finish.

There are essentially three responses to the scarcity of acceptable SnPb parts: custom order, post process or adapt. Custom ordering parts with SnPb finishes negates the benefits of COTS based acquisition, however, has a reduced reliability risk because the material and processes are known. Reprocessing parts once in house saves money because the parts are COTS, but expends money and resources by performing post processing on them. Additionally, the additional touch labor and handling increases the risk of damaging the part. Finally, adapting to Pb-free finishes is the preferred long term approach because it preserves the cost benefits of using COTS parts and does not require post processing. It is the riskiest approach due to the lack of historical data.